Methods and circuits for distributing power to SPD loads

Abstract

Methods and circuits for distributing power to suspended-particle-device (SPD) film products including SPD windows, SPD shades, and other SPD products, which are referred to generally as SPD loads. A driving voltage derived from a primary power source is provided to an SPD load by backbone wiring which carries a low AC or DC voltage derived from the primary power source, and a conversion stage which converts the low voltage to an AC driving voltage which is then supplied to the SPD load.

1. An arrangement for providing a driving voltage from a primary power source to one or more SPD loads, comprising in combination:
 backbone wiring which carries a low voltage derived from said primary power source; and 
 a conversion stage which converts said low voltage to a higher voltage AC driving voltage and supplies said AC driving voltage to said one or more SPD loads. 
 
     
     
       2. An arrangement according to  claim 1 , wherein said low voltage is substantially 12 VAC. 
     
     
       3. An arrangement according to  claim 1 , wherein said low voltage is substantially 12 VDC. 
     
     
       4. An arrangement according to  claim 1 , wherein said primary power source supplies AC, said low voltage on said backbone wiring is AC, said conversion stage comprises at least one step-up transformer, and further comprising a step-down transformer which steps down said supplied AC to said low AC voltage on said backbone wiring. 
     
     
       5. An arrangement according to  claim 1 , wherein said primary power source supplies DC, and said conversion stage comprises at least one DC-AC step-up converter which supplies said AC driving voltage to at least one said SPD load. 
     
     
       6. An arrangement according to  claim 5 , wherein said SPD loads comprise windows, and said corresponding DC-AC step-up converters are assembled into said windows. 
     
     
       7. An arrangement according to  claim 5 , wherein said primary power source comprises a battery which supplies said low DC voltage. 
     
     
       8. An arrangement according to  claim 7 , further comprising a solar cell which powers a charger for said battery. 
     
     
       9. An arrangement according to  claim 5 , further comprising at least one dc-ac step-up converter which receives said low DC voltage on said backbone wiring and supplies said AC driving voltage. 
     
     
       10. A method of providing a driving voltage from a primary power source to one or more SPD loads, comprising the steps of:
 feeding a low voltage derived from said primary power source to backbone wiring; and converting said low voltage to a higher voltage AC driving voltage and supplying said AC driving voltage to said one or more SPD loads. 
 
     
     
       11. A method according to  claim 10 , wherein said low voltage is substantially 12 VAC. 
     
     
       12. A method according to  claim 10 , wherein said low voltage is substantially 12 VDC. 
     
     
       13. A method according to  claim 10 , wherein said primary power source supplies AC, said low voltage on said backbone wiring is AC, and further comprising the steps of using a step-down transformer to step down said supplied AC to said low AC voltage on said backbone wiring, and using at least one step-up transformer for converting said low voltage to said AC driving voltage. 
     
     
       14. A method according to  claim 13 , further comprising the step of providing a respective step-up transformer for each of said SPD loads. 
     
     
       15. A method according to  claim 10 , wherein said primary power source supplies DC, and comprising the step of providing at least one DC-AC step-up converter for supplying said AC driving voltage to at least one said SPD load. 
     
     
       16. A method according to  claim 15 , wherein said SPD loads comprise windows, further comprising the step of assembling said corresponding DC-AC step-up converters into said windows. 
     
     
       17. A method according to  claim 15 , further comprising the step of providing a battery as said primary power source which supplies said low DC voltage. 
     
     
       18. A method according to  claim 17 , further comprising the step of providing a solar cell for powering a charger for said battery. 
     
     
       19. A method according to  claim 17 , further comprising the step of reducing an operating frequency of said DC-AC step-up converter, thereby reducing SPD load current without causing noticeable flicker. 
     
     
       20. A method according to  claim 19 , wherein said operating frequency is reduced to substantially about 10-15 Hz. 
     
     
       21. A method according to  claim 20 , wherein said operating frequency is reduced to about 15 Hz. 
     
     
       22. A method according to  claim 17 , further comprising the step of providing at least one dc-ac step-up converter which receives said low DC voltage on said backbone wiring and supplies said AC driving voltage. 
     
     
       23. A method according to  claim 22 , further comprising the step of providing a plurality of step-up dc-ac converters for supplying said AC driving voltage. 
     
     
       24. A method according to  claim 23 , comprising the step of providing a respective step-up dc-ac converter for each of said SPD loads. 
     
     
       25. A method according to  claim 15 , further comprising the step of providing at least one dc-ac step-up converter which receives said low DC voltage on said backbone wiring and supplies said AC driving voltage. 
     
     
       26. A method according to  claim 25 , further comprising the step of providing a plurality of step-up dc-ac converters for supplying said AC driving voltage. 
     
     
       27. A method according to  claim 26 , comprising the step of providing a respective step-up dc-ac converter for each of said SPD loads.